This invention relates to aqueous emulsions comprising a water-dispersible copolymer which is non-dispersible in aqueous solutions containing 0.5% or more of an inorganic salt, comprising acidic ethylenically unsaturated monomers and ethylenically unsaturated monomers. The acidic ethylenically unsaturated monomers and the ethylenically unsaturated monomers are defined herein. The present invention also pertains to emulsion polymerization methods for making the aqueous emulsions with or without a surfactant.
Water-soluble polymers, soluble in tap water but insoluble in dilute salt solutions, are known in the art, however many of these water-soluble polymer compositions are not entirely satisfactory. Moreover, many water-soluble copolymers require alkali to remove the polymeric film which is often difficult and unsafe for the consumer. The present invention provides improved water-dispersible copolymer compositions without the disadvantages characteristic of previously known compositions.
In a first embodiment, the present invention is directed to an aqueous emulsion comprising a water-dispersible copolymer which is non-dispersible in aqueous solutions containing 0.5% or more of an inorganic salt, wherein the water-dispersible copolymer comprises in percentages by weight:
(A) from about 10% to about 90% of an acidic ethylenically unsaturated monomer; and
(B) from about 10% to about 90% of an ethylenically unsaturated monomer selected from the group of monomer formulas consisting of:
(i) CH2xe2x95x90C(R1)COR2;
(ii) R3OOCxe2x80x94CHxe2x95x90CHxe2x80x94COOR4;
(iii) CH2xe2x95x90C(R5)OCOR6;
(iv) CH2xe2x95x90C(COOR7)CH2COOR8;
(v) CH3CHxe2x95x90CHCOOR9;
(vi) R10C6H4CR11xe2x95x90CHR11; and
(vii) R12CHxe2x95x90CHR13;
xe2x80x83wherein R1 is hydrogen or methyl and R2 is xe2x80x94OZxe2x80x2 or xe2x80x94N(Zxe2x80x3)(Zxe2x80x3), wherein Zxe2x80x2 is an alkyl group having from 1 to 7 carbon atoms, and Zxe2x80x3 is independently selected from the group consisting of hydrogen and alkyl groups having from 1 to 6 carbon atoms; R3 and R4 are independently hydrogen or an alkyl group having from 1 to 7 carbon atoms, with the proviso that R3 and R4 are not both hydrogen; R5 is hydrogen or methyl and R6 is an alkyl group having from 1 to 7 carbon atoms; R7 and R8 are independently hydrogen or an alkyl group having from 1 to 7 carbon atoms, with the proviso that R7 and R8 are not both hydrogen; R9 is an alkyl group having from 1 to 7 carbon atoms; R10 and R11 are hydrogen; R12 and R13 are independently selected from the group consisting of hydrogen, xe2x80x94CN, xe2x80x94NHCHO, xe2x80x94NHCOCH3, and an alkyl group having from 1 to 7 carbon atoms; and the copolymer has a weight average molecular weight greater than about 25,000 and is present in an amount from about 20% to about 70%.
In a second embodiment, the present invention is directed to an aqueous emulsion comprising a water-dispersible copolymer which is non-dispersible in aqueous solutions containing 0.5% or more of an inorganic salt, wherein the water-dispersible copolymer comprises in percentages by weight:
(A) from about 10% to about 90% of an acidic ethylenically unsaturated monomer; and
(B) from about 10% to about 90% of an ethylenically unsaturated monomer selected from the group of monomer formulas consisting of:
(i) CH2xe2x95x90C(Rxe2x80x21)CORxe2x80x22;
(ii) Rxe2x80x23OOCxe2x80x94CHxe2x95x90CHxe2x80x94COORxe2x80x24;
(iii) CH2xe2x95x90C(Rxe2x80x25)OCORxe2x80x26;
(iv) CH2xe2x95x90C(COORxe2x80x27)CH2COORxe2x80x28;
(v) CH3CHxe2x95x90CHCOORxe2x80x29;
(vi) Rxe2x80x210C6H4CRxe2x80x211xe2x95x90CHRxe2x80x211; and
(vii) Rxe2x80x212CHxe2x95x90CHRxe2x80x213;
xe2x80x83wherein Rxe2x80x21 is hydrogen or methyl, and Rxe2x80x22 is selected from the group consisting of xe2x80x94OZxe2x80x2, xe2x80x94N(Zxe2x80x3)(Zxe2x80x3), and xe2x80x94OZxe2x80x2xe2x80x3OH, wherein Zxe2x80x2 is an alkyl group having from 8 to 18 carbon atoms; Zxe2x80x3 is independently selected from the group consisting of alkyl groups having from 7 to 10 carbon atoms, dimethylamino alkyl groups having from 1 to 5 carbon atoms, and hydroxyalkyl groups having from 1 to 5 carbon atoms; and Zxe2x80x2xe2x80x3 is an alkyl group having from 1 to 4 carbon atoms; Rxe2x80x23 and Rxe2x80x24 are independently an alkyl group having from 8 to 18 carbon atoms; Rxe2x80x25 is hydrogen or methyl and Rxe2x80x26 is an alkyl group having from 8 to 18 carbon atoms; Rxe2x80x27 and Rxe2x80x28 are independently an alkyl group having from 8 to 18 carbon atoms; Rxe2x80x29 is an alkyl group having from 8 to 18 carbon atoms; Rxe2x80x210 and Rxe2x80x211 are independently an alkyl group having from 1 to 2 carbon atoms; Rxe2x80x212 and Rxe2x80x213 are independently selected from the group consisting of 2-pyrrolidinone, N-caprolactam, 2-pyridine, 3-pyridine, 4-pyridine, and an alkyl group having from 7 to 18 carbon atoms, with the proviso that R12 and R13 are not at the same time 2-pyrrolidinone, N-caprolactam, 2-pyridine, 3-pyridine, or 4-pyridine; and the copolymer has a weight average molecular weight greater than about 25,000 and is present in an amount from about 20% to about 70%.
In a third embodiment, the present invention is directed to an aqueous emulsion comprising a water-dispersible copolymer which is non-dispersible in aqueous solutions containing 0.5% or more of an inorganic salt, wherein the water-dispersible copolymer comprises in percentages by weight:
(A) from about 10% to about 80% of an acidic ethylenically unsaturated monomer, with the proviso that the acidic ethylenically unsaturated monomer is not acrylic acid;
(B) from about 10% to about 80% of an ethylenically unsaturated monomer selected from the group of monomer formulas consisting of:
(i) CH2xe2x95x90C(R1)COR2;
(ii) R3OOCxe2x80x94CHxe2x95x90CHxe2x80x94COOR4;
(iii) CH2xe2x95x90C(R5)OCOR6;
(iv) CH2xe2x95x90C(COOR7)CH2COOR8;
(v) CH3CHxe2x95x90CHCOOR9;
(vi) R10C6H4CR11xe2x95x90CHR11; and
(vii) R12CHxe2x95x90CHR13;
xe2x80x83wherein R1 is hydrogen or methyl and R2 is xe2x80x94OZxe2x80x2 or xe2x80x94N(Zxe2x80x3)(Zxe2x80x3), wherein Zxe2x80x2 is an alkyl group having from 1 to 7 carbon atoms, and Zxe2x80x3 is independently selected from the group consisting of hydrogen and alkyl groups having from 1 to 6 carbon atoms; R3 and R4 are independently hydrogen or an alkyl group having from 1 to 7 carbon atoms, with the proviso that R3 and R4 are not both hydrogen; R5 is hydrogen or methyl and R6 is an alkyl group having from 1 to 7 carbon atoms; R7 and R8 are independently hydrogen or an alkyl group having from 1 to 7 carbon atoms, with the proviso that R7 and R8 are not both hydrogen; R9 is an alkyl group having from 1 to 7 carbon atoms; R10 and R11 are hydrogen; and R12 and R13 are independently selected from the group consisting of hydrogen, xe2x80x94CN, xe2x80x94NHCHO, and an alkyl group having from 1 to 7 carbon atoms; and
(C) from about 10% to about 80% of an ethylenically unsaturated monomer selected from the group of monomer formulas consisting of:
(i) CH2xe2x95x90C(Rxe2x80x21)CORxe2x80x22;
(ii) Rxe2x80x23OOCxe2x80x94CHxe2x95x90CHxe2x80x94COORxe2x80x24;
(iii) CH2xe2x95x90C(Rxe2x80x25)OCORxe2x80x26;
(iv) CH2xe2x95x90C(COORxe2x80x27)CH2COORxe2x80x28;
(v) CH3CHxe2x95x90CHCOORxe2x80x29;
(vi) Rxe2x80x210C6H4CRxe2x80x211xe2x95x90CHRxe2x80x211; and
(vii) Rxe2x80x212CHxe2x95x90CHRxe2x80x213;
xe2x80x83wherein Rxe2x80x21 is hydrogen or methyl, and Rxe2x80x22 is selected from the group consisting of xe2x80x94OZxe2x80x2, xe2x80x94N(Zxe2x80x3)(Zxe2x80x3), and xe2x80x94OZxe2x80x2xe2x80x3OH, wherein Zxe2x80x2 is an alkyl group having from 8 to 18 carbon atoms; Zxe2x80x3 is independently selected from the group consisting of alkyl groups having from 7 to 10 carbon atoms, dimethylamino alkyl groups having from 1 to 5 carbon atoms, and hydroxyalkyl groups having from 1 to 5 carbon atoms; and Zxe2x80x2xe2x80x3 is an alkyl group having from 1 to 4 carbon atoms; Rxe2x80x23 and Rxe2x80x24 are independently an alkyl group having from 8 to 18 carbon atoms; Rxe2x80x25 is hydrogen or methyl and Rxe2x80x26 is an alkyl group having from 8 to 18 carbon atoms; Rxe2x80x27 and Rxe2x80x28 are independently an alkyl group having from 8 to 18 carbon atoms; Rxe2x80x29 is an alkyl group having from 8 to 18 carbon atoms; Rxe2x80x210 and Rxe2x80x211 are independently an alkyl group having from 1 to 2 carbon atoms; Rxe2x80x212 and Rxe2x80x213 are independently selected from the group consisting of 2-pyrrolidinone, N-caprolactam, and an alkyl group having from 7 to 18 carbon atoms, with the proviso that R12 and R13 are not both 2-pyrrolidinone, are not both N-caprolactam, or are not a mixture thereof; and the copolymer has a weight average molecular weight greater than about 25,000 and is present in an amount from about 20% to about 70%.
The present invention is also directed to methods for preparing the aqueous emulsions in the above embodiments. A first method comprises the steps of (a) providing the monomers in one of the above embodiments; and (b) emulsion polymerizing the monomers in water at a solids level from about 20% to about 70% in the presence of a surfactant. A second method comprises the steps of (a) providing the monomers in one of the above embodiments; (b) neutralizing the monomers in water to a level from about 2% to about 15% molar of the acidic ethylenically unsaturated monomer from (A); and (c) emulsion polymerizing the monomers at a solids level from about 20% to about 60% without a surfactant.
In accord with the present invention, aqueous emulsions comprising water-dispersible copolymers are provided that are non-dispersible in dilute inorganic salt solutions. The salt-sensitive copolymers are soluble/dispersible in tap water but are non-dispersible in water containing at least 0.5% of an inorganic monovalent, divalent, or trivalent salt. The water-dispersible copolymers are prepared from acidic ethylenically unsaturated monomers and a variety of other ethylenically unsaturated monomers. By carefully selecting the type and amount of the acidic ethylenically unsaturated monomer, one can obtain copolymer products having good hydrophilic properties such that the copolymer is water-dispersible, especially when partially neutralized, but is non-dispersible in dilute inorganic salt solutions. By carefully selecting the type and amount of the other ethylenically unsaturated monomers, one can obtain copolymer products useful for non-woven fabrics or papers having good wet strength and permeability to body fluids. The water-dispersible copolymers may be employed in protective top coats, floor polishes, temporary printing, adhesives, skin creams, sun screens, hair fixatives, temporary decorative paints, marine coatings, repulpable paper coatings, glass fiber sizing, time release/erodible coatings or particles, and antiperspirant-film not removed by perspiration but removed by soap and water.
Unlike conventional water-soluble polymers, the aqueous emulsions of the present invention do not require divalent ion inhibitors. Film formation of latexes differs from film formation of solution polymers since particle coalescence is needed to form a film of high cohesive strength in emulsion polymers. For solution polymers, particle coalescence is not necessary because the solvent acts as a plasticizer which aids in the film formation by allowing polymer chains to mix and entangle. For emulsion polymers, the cohesive strength of the polymer film is reduced if the particles do not fully coalesce because of the reduction of chain entanglements. For emulsion polymers, the surface active layer remains as an interfacial boundary between particles and prevents full chain entanglement to the extent observed from solution polymers. As a result, films derived from the aqueous emulsions of the present invention will readily disperse in the presence of water. In addition, the novel polymer film will also disperse in hard water since divalent ions do not inhibit the redispersability by the film derived from emulsions. In contrast, for polymer films derived solution, hard water is less effective in solubilizing the polymer since divalent ions inhibit the movement of the highly entangled polymer chains. For films derived from solution polymers, ion regulating agents are required to enhance the solubilzation in hard water. This is the main reason why the aqueous emulsions of the present invention do not require a divalent ion inhibitor (sequestering agent) to aid in the redispersablility in tap water, especially hard water. Preferably the particle size of the water-dispersible copolymer is from about 0.05 micron to about 0.8 micron.
The present invention also provides emulsion polymerization methods to form stable, low viscosity, emulsions of the water-dispersible copolymers both with the use of surfactants and without the use of surfactants (in situ stabilization). In the surfactant embodiment, a seeded or unseeded process is utilized to copolymerize an acidic ethylenically unsaturated monomer, such as an unsaturated carboxylic acid monomer, and other ethylenically unsaturated monomers, such as alkyl (meth)acrylate(s) or vinyl monomer(s), in water with a surfactant. In the non-surfactant embodiment, the monomers are first neutralized in water to a level from about 2% to about 15% molar of the acidic ethylenically unsaturated monomer, and the resulting emulsion is then polymerized without a surfactant. In a preferred (non-surfactant) method, a seed polymer is polymerized in water with the first stage comprising the acidic ethylenically unsaturated monomer, and other ethylenically unsaturated monomers, which are at least partially neutralized (10% to 100%) with aqueous ammonia to form the in situ stabilizer colloid. In the second stage, this colloid is copolymerized with 100 parts of an ethylenically unsaturated monomer, such as acrylic monomers like 2-ethyl hexyl acrylate, styrene, butyl acrylate, ethyl acrylate, acrylic acid, methacrylic acid, etc. and/or vinyl acetate, monoethyl maleate, maleic acid, itaconic acid, etc. When the emulsions are dried, the resulting film particles are dispersible in water since the copolymer contains a high concentration of hydrophilic monomers, such as acidic functionality. This acidic functionality also prevents the particles from dispersing in aqueous salt solutions. To further improve water dispersability, a chain transfer agent, or polymerization terminator, such as dodecyl mercaptan, may be added to reduce the molecular weight of the polymer during the polymerization process. Typical emulsion polymerizations are batch, semi-batch, slow-addition, and continuous processes. Monomers can be slow added linearly, or via gradient simultaneously, or separately.
As set out above, the salt-sensitive copolymers are soluble/dispersible in tap water but are non-dispersible in water containing at least 0.5% of an inorganic monovalent, divalent, or trivalent metal salt. Examples of monovalent inorganic metal salts include sodium chloride, potassium phosphate, and sodium acetate. Examples of divalent inorganic metal salts include magnesium chloride, barium chloride, calcium chloride, calcium carbonate, and magnesium acetate. Examples of trivalent inorganic metal salts include aluminum chloride, boron chloride, and aluminum acetate.
The term xe2x80x9calkyl groupxe2x80x9d, as used herein, refers to branched or unbranched hydrocarbon groups as well as cyclic and bicyclic hydrocarbon groups. The term halogen, as used herein, refers to the chemically related elements consisting of fluorine, chlorine, bromine and iodine.
In a first embodiment, the present invention is directed to an aqueous emulsion comprising a water-dispersible copolymer which is non-dispersible in aqueous solutions containing 0.5% or more of an inorganic salt, wherein the water-dispersible copolymer comprises in percentages by weight:
(A) from about 10% to about 90% of an acidic ethylenically unsaturated monomer; and
(B) from about 10% to about 90% of an ethylenically unsaturated monomer selected from the group of monomer formulas consisting of:
(i) CH2xe2x95x90C(R1)COR2;
(ii) R3OOCxe2x80x94CHxe2x95x90CHxe2x80x94COOR4;
(iii) CH2xe2x95x90C(R5)OCOR6;
(iv) CH2xe2x95x90C(COOR7)CH2COOR8;
(v) CH3CHxe2x95x90CHCOOR9;
(vi) R10C6H4CR11xe2x95x90CHR11; and
(vii) R12CHxe2x95x90CHR13;
xe2x80x83wherein R1 is hydrogen or methyl and R2 is xe2x80x94OZxe2x80x2 or xe2x80x94N(Zxe2x80x3)(Zxe2x80x3), wherein Zxe2x80x2 is an alkyl group having from 1 to 7 carbon atoms, and Zxe2x80x3 is independently selected from the group consisting of hydrogen and alkyl groups having from 1 to 6 carbon atoms; R3 and R4 are independently hydrogen or an alkyl group having from 1 to 7 carbon atoms, with the proviso that R3 and R4 are not both hydrogen; R5 is hydrogen or methyl and R6 is an alkyl group having from 1 to 7 carbon atoms; R7 and R8 are independently hydrogen or an alkyl group having from 1 to 7 carbon atoms, with the proviso that R7 and R8 are not both hydrogen; R9 is an alkyl group having from 1 to 7 carbon atoms; R10 and R11 are hydrogen; R12 and R13 are independently selected from the group consisting of hydrogen, xe2x80x94CN, xe2x80x94NHCHO, xe2x80x94NHCOCH3, and an alkyl group having from 1 to 7 carbon atoms; and the copolymer has a weight average molecular weight greater than about 25,000 and is present in an amount from about 20% to about 70%.
In this embodiment, the acidic ethylenically unsaturated monomers from (A) may be selected from the group consisting of monomers containing a carboxylic acid group, monomers containing a sulfonic acid group, and monomers containing a phosphoric acid group. Examples of monomers containing a carboxylic acid group may be selected from the group consisting of acrylic acid, methacrylic acid, maleic acid, maleic acid half esters, maleic anhydride, itaconic acid, and crotonic acid. Preferably, the monomer containing a carboxylic acid group is methacrylic acid. Examples of monomers containing a sulfonic acid group may be selected from the group consisting of styrene sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid, and sodium vinyl sulfonate. Preferably, the monomer containing a sulfonic acid group is styrene sulfonic acid or 2-acrylamido-2-methylpropane sulfonic acid. Examples of monomers containing a phosphoric acid group may be selected from the group consisting of styrene phosphoric acid, sodium vinyl phosphonate, and CH2xe2x95x90C(CH3)COO(CH2)nOPO3H, wherein n is from 2 to 4. Preferably, the monomer containing a phosphoric acid group is CH2xe2x95x90C(CH3)COO(CH2)nOPO3H, wherein n is from 2 to 4.
Preferably, the ethylenically unsaturated monomer from (B) is (i) CH2xe2x95x90C(R1)COR2, wherein R1 is methyl and R2 is xe2x80x94OZxe2x80x21 wherein Zxe2x80x2 is an alkyl group having from 1 to 4 carbon atoms. Examples of the ethylenically unsaturated monomer from (B) (i), CH2xe2x95x90C(R1)COR2, may be selected from the group of (meth)acrylamides consisting of (meth)acrylamide, N-methyl (meth)acrylamide, N-ethyl (meth)acrylamide, N-propyl (meth)acrylamide, N-butyl (meth)acrylamide, N-pentyl (meth)acrylamide, N-hexyl (meth)acrylamide, N-heptyl (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, N,N-dipropyl (meth)acrylamide, and N,N-dibutyl (meth)acrylamide. Other examples of the ethylenically unsaturated monomer from (B) (i), CH2xe2x95x90C(R1)COR2, may be selected from the group of (meth)acrylates consisting of methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, dimethyl (meth)acrylate, diethyl (meth)acrylate, dipropyl (meth)acrylate, and dibutyl (meth)acrylate.
Preferably, the ethylenically unsaturated monomer from (B) is (ii) R3OOCxe2x80x94CHxe2x95x90CHxe2x80x94COOR4, wherein R3 and R4 are independently an alkyl group having from 1 to 4 carbon atoms, more preferably from 2 to 4 carbon atoms.
Preferably, the ethylenically unsaturated monomer from (B) is (iii) CH2xe2x95x90C(R5)OCOR6, wherein R5 is methyl and R6 is an alkyl group having from 1 to 4 carbon atoms. Examples of the ethylenically unsaturated monomer from (B) (iii), CH2xe2x95x90C(R5)OCOR6, may be selected from the group consisting of vinyl formate, vinyl acetate, vinyl propionate, vinyl isobutyrate, and vinyl pivalate.
Preferably, the ethylenically unsaturated monomer from (B) is (iv) CH2xe2x95x90C(COOR7)CH2COOR8, wherein R7 and R8 are independently an alkyl group having from 1 to 4 carbon atoms, more preferably from 2 to 4 carbon atoms. Preferably, the ethylenically unsaturated monomer from (B) is (v) CH3CHxe2x95x90CHCOOR9, wherein R9 is an alkyl group having from 1 to 4 carbon atoms, more preferably from 2 to 4 carbon atoms. Preferably, the ethylenically unsaturated monomer from (B) is (vi) styrene.
Preferably, the ethylenically unsaturated monomer from (B) is (vii) R12CHxe2x95x90CHR13, wherein R12 and R13 are independently hydrogen or methyl. Examples of the ethylenically unsaturated monomer from (B) (vii), R12CHxe2x95x90CHR13, may be selected from the group consisting of ethylene, propylene, butylene, butadiene, acrylonitrile, N-vinyl formamide, and vinyl acetamide.
In this embodiment, the exact amount of acidic ethylenically unsaturated monomer from (A) and ethylenically unsaturated monomer from (B) present in the water-dispersible copolymer is a matter of preference subject to such factors as the particular type of ethylenically unsaturated monomer employed, the molecular weight of the water-dispersible copolymer employed, and are particular to the end use application. In a preferred embodiment, the acidic ethylenically unsaturated monomer from (A) is present in the water-dispersible copolymer in an amount from about 10% to about 90%, preferably from about 25% to about 75%, more preferably from about 30% to about 70%, and most preferably from about 35% to about 65%, by weight. In a preferred embodiment, the ethylenically unsaturated monomer from (B) is present in the water-dispersible copolymer in an amount from about 10% to about 90%, preferably from about 25% to about 75%, more preferably from about 30% to about 70%, and most preferably from about 35% to about 65%, by weight.
In a second embodiment, the present invention is directed to an aqueous emulsion comprising a water-dispersible copolymer which is non-dispersible in aqueous solutions containing 0.5% or more of an inorganic salt, wherein the water-dispersible copolymer comprises in percentages by weight:
(A) from about 10% to about 90% of an acidic ethylenically unsaturated monomer; and
(B) from about 10% to about 90% of an ethylenically unsaturated monomer selected from the group of monomer formulas consisting of:
(i) CH2xe2x95x90C(Rxe2x80x21)CORxe2x80x22;
(ii) Rxe2x80x23OOCxe2x80x94CHxe2x95x90CHxe2x80x94COORxe2x80x24;
(iii) CH2xe2x95x90C(Rxe2x80x25)OCORxe2x80x26;
(iv) CH2xe2x95x90C(COORxe2x80x27)CH2COORxe2x80x28;
(v) CH3CHxe2x95x90CHCOORxe2x80x29;
(vi) Rxe2x80x210C6H4CRxe2x80x211xe2x95x90CHRxe2x80x211; and
(vii) Rxe2x80x212CHxe2x95x90CHRxe2x80x213;
xe2x80x83wherein Rxe2x80x21 is hydrogen or methyl, and Rxe2x80x22 is selected from the group consisting of xe2x80x94OZxe2x80x2, xe2x80x94N(Zxe2x80x3)(Zxe2x80x3), and xe2x80x94OZxe2x80x2xe2x80x3OH, wherein Zxe2x80x2 is an alkyl group having from 8 to 18 carbon atoms; Zxe2x80x3 is independently selected from the group consisting of alkyl groups having from 7 to 10 carbon atoms, dimethylamino alkyl groups having from 1 to 5 carbon atoms, and hydroxyalkyl groups having from 1 to 5 carbon atoms; and Zxe2x80x2xe2x80x3 is an alkyl group having from 1 to 4 carbon atoms; Rxe2x80x23 and Rxe2x80x24 are independently an alkyl group having from 8 to 18 carbon atoms; Rxe2x80x25 is hydrogen or methyl and Rxe2x80x26 is an alkyl group having from 8 to 18 carbon atoms; Rxe2x80x27 and Rxe2x80x28 are independently an alkyl group having from 8 to 18 carbon atoms; Rxe2x80x29 is an alkyl group having from 8 to 18 carbon atoms; Rxe2x80x210 and Rxe2x80x211 are independently an alkyl group having from 1 to 2 carbon atoms; Rxe2x80x212 and Rxe2x80x213 are independently selected from the group consisting of 2-pyrrolidinone, N-caprolactam, 2-pyridine, 3-pyridine, 4-pyridine, and an alkyl group having from 7 to 18 carbon atoms, with the proviso that R12 and R13 are not at the same time 2-pyrrolidinone, N-caprolactam, 2-pyridine, 3-pyridine, or 4-pyridine; and the copolymer has a weight average molecular weight greater than about 25,000 and is present in an amount from about 20% to about 70%.
The acidic ethylenically unsaturated monomers from (A) in this embodiment are as defined above.
Preferably, the ethylenically unsaturated monomer from (B) is (i) CH2xe2x95x90C(Rxe2x80x21)CORxe2x80x22, wherein Rxe2x80x21 is methyl, Rxe2x80x22 is selected from the group consisting of xe2x80x94OZxe2x80x2, xe2x80x94N(Zxe2x80x3)(Zxe2x80x3), and xe2x80x94OZxe2x80x2xe2x80x3OH, wherein Zxe2x80x2 is an alkyl group having from 8 to 12 carbon atoms, preferably from 9 to 11 carbon atoms; Zxe2x80x3 is independently selected from the group consisting of alkyl groups having from 8 to 10 carbon atoms, dimethylamino alkyl groups having from 1 to 3 carbon atoms, and hydroxyalkyl groups having from 1 to 3 carbon atoms; and Zxe2x80x2xe2x80x3 is an alkyl group having from 1 to 2 carbon atoms. Examples of the ethylenically unsaturated monomer from (B) (i), CH2xe2x95x90C(Rxe2x80x21)CORxe2x80x22, may be selected from the group of (meth)acrylamides consisting of N-t-octyl (meth)acrylamide, N,N-di-t-octyl (meth)acrylamide, 2-(dimethylamino)ethyl (methacrylate), N-[3-(dimethylamino)propyl] (meth)acrylamide, N-(hydroxymethyl) (meth)acrylamide, and N-(isobutoxymethyl)acrylamide. Other examples of the ethylenically unsaturated monomer from (B) (i), CH2xe2x95x90C(Rxe2x80x21)CORxe2x80x22, may be selected from the group of (meth)acrylates consisting of 2-ethyl hexyl (meth)acrylate, octyl (meth)acrylate, t-octyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, isobomyl (meth)acrylate, lauryl (meth)acrylate, and steryl (meth)acrylate. Other examples of the ethylenically unsaturated monomer from (B) (i), CH2xe2x95x90C(Rxe2x80x21)CORxe2x80x22, may be selected from the group of hydroxy (meth)acrylates consisting of 1-hydroxymethyl (meth)acrylate, 2-hydroxymethyl (meth)acrylate, 1-hydroxyethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 1-hydroxypropyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 3-hydroxypropyl (meth)acrylate.
Preferably, the ethylenically unsaturated monomer from (B) is (ii) Rxe2x80x23OOCxe2x80x94CHxe2x95x90CHxe2x80x94COORxe2x80x24, wherein Rxe2x80x23 and Rxe2x80x24 are independently an alkyl group having from 8 to 12 carbon atoms, preferably from 9 to 11 carbon atoms.
Preferably, the ethylenically unsaturated monomer from (B) is (iii) CH2xe2x95x90C(Rxe2x80x25)OCORxe2x80x26, wherein Rxe2x80x25 is methyl, and Rxe2x80x26 is an alkyl group having from 8 to 12 carbon atoms, preferably from 9 to 11 carbon atoms. Examples of the ethylenically unsaturated monomer from (B) iii), CH2xe2x95x90C(Rxe2x80x25)OCORxe2x80x26, and is selected from the group consisting of vinyl 2-ethylhexonate, vinyl p-t-butyl benzoate, vinyl esters of versatic acid, vinyl laurate, and vinyl stearate.
Preferably, the ethylenically unsaturated monomer from (B) is (iv) CH2xe2x95x90C(COORxe2x80x27)CH2COORxe2x80x28, wherein Rxe2x80x27 and Rxe2x80x28 are independently an alkyl group having from 8 to 12 carbon atoms, preferably from 9 to 11 carbon atoms. Preferably, the ethylenically unsaturated monomer from (B) is (v) CH3CHxe2x95x90CHCOORxe2x80x29, and Rxe2x80x29 is an alkyl group having from 8 to 12 carbon atoms, preferably from 9 to 11 carbon atoms. Preferably, the ethylenically unsaturated monomer from (B) is (vi) Rxe2x80x210C6H4CRxe2x80x211xe2x95x90CHRxe2x80x211, and Rxe2x80x210 and Rxe2x80x211 are independently methyl.
Preferably, the ethylenically unsaturated monomer from (B) is (vii) Rxe2x80x212CHxe2x95x90CHRxe2x80x213, wherein Rxe2x80x212 and Rxe2x80x213 are independently selected from the group consisting of 2-pyrrolidinone, N-caprolactam, 2-pyridine, 3-pyridine, 4-pyridine, and an alkyl group having from 7 to 12 carbon atoms, preferably from 8 to 11 carbon atoms. Examples of the ethylenically unsaturated monomer from (B) (vii), Rxe2x80x212CHxe2x95x90CHRxe2x80x213, and is independently selected from the group consisting of vinyl 2-pyrrolidinone, vinyl N-caprolactam, and an alkyl group having from 7 to 12 carbon atoms, preferably from 8 to 11 carbon atoms.
In this embodiment, the exact amount of acidic ethylenically unsaturated monomer from (A) and ethylenically unsaturated monomer from (B) present in the water-dispersible copolymer is a matter of preference subject to such factors as the particular type of ethylenically unsaturated monomer employed, the molecular weight of the water-dispersible copolymer employed, and are particular to the end use application. In a preferred embodiment, the acidic ethylenically unsaturated monomer from (A) is present in the water-dispersible copolymer in an amount from about 10% to about 90%, preferably from about 25% to about 75%, more preferably from about 30% to about 70%, and most preferably from about 35% to about 65%, by weight. In a preferred embodiment, the ethylenically unsaturated monomer from (B) is present in the water-dispersible copolymer in an amount from about 10% to about 90%, preferably from about 25% to about 75%, more preferably from about 30% to about 70%, and most preferably from about 35% to about 65%, by weight.
In a third embodiment, the present invention is directed to an aqueous emulsion comprising a water-dispersible copolymer which is non-dispersible in aqueous solutions containing 0.5% or more of an inorganic salt, wherein the water-dispersible copolymer comprises in percentages by weight:
(A) from about 10% to about 80% of an acidic ethylenically unsaturated monomer, with the proviso that the acidic ethylenically unsaturated monomer is not acrylic acid;
(B) from about 10% to about 80% of an ethylenically unsaturated monomer selected from the group of monomer formulas consisting of:
(i) CH2xe2x95x90C(R1)COR2;
(ii) R3OOCxe2x80x94CHxe2x95x90CHxe2x80x94COOR4;
(iii) CH2xe2x95x90C(R5)OCOR6;
(iv) CH2xe2x95x90C(COOR7)CH2COOR8;
(v) CH3CHxe2x95x90CHCOOR9;
(vi) R10C6H4CR11xe2x95x90CHR11; and
(vii) R12CHxe2x95x90CHR13;
xe2x80x83wherein R1 is hydrogen or methyl and R2 is xe2x80x94OZxe2x80x2 or xe2x80x94N(Zxe2x80x3) (Zxe2x80x3), wherein Zxe2x80x2 is an alkyl group having from 1 to 7 carbon atoms, and Zxe2x80x3 is independently selected from the group consisting of hydrogen and alkyl groups having from 1 to 6 carbon atoms; R3 and R4 are independently hydrogen or an alkyl group having from 1 to 7 carbon atoms, with the proviso that R3 and R4 are not both hydrogen; R5 is hydrogen or methyl and R6 is an alkyl group having from 1 to 7 carbon atoms; R7 and R8 are independently hydrogen or an alkyl group having from 1 to 7 carbon atoms, with the proviso that R7 and R8 are not both hydrogen; R9 is an alkyl group having from 1 to 7 carbon atoms; R10 and R11 are hydrogen; and R12 and R13 are independently selected from the group consisting of hydrogen, xe2x80x94CN, xe2x80x94NHCHO, and an alkyl group having from 1 to 7 carbon atoms; and
(C) from about 10% to about 80% of an ethylenically unsaturated monomer selected from the group of monomer formulas consisting of:
(i) CH2xe2x95x90C(Rxe2x80x21)CORxe2x80x22;
(ii) Rxe2x80x23OOCxe2x80x94CHxe2x95x90CHxe2x80x94COORxe2x80x24;
(iii) CH2xe2x95x90C(Rxe2x80x25)OCORxe2x80x26;
(iv) CH2xe2x95x90C(COORxe2x80x27)CH2COORxe2x80x28;
(v) CH3CHxe2x95x90CHCOORxe2x80x29;
(vi) Rxe2x80x210C6H4CRxe2x80x211xe2x95x90CHRxe2x80x211; and
(vii) Rxe2x80x212CHxe2x95x90CHRxe2x80x213;
xe2x80x83wherein Rxe2x80x21 is hydrogen or methyl, and Rxe2x80x22 is selected from the group consisting of xe2x80x94OZxe2x80x2, xe2x80x94N(Zxe2x80x3)(Zxe2x80x3), and xe2x80x94OZxe2x80x2xe2x80x3OH, wherein Zxe2x80x2 is an alkyl group having from 8 to 18 carbon atoms; Zxe2x80x3 is independently selected from the group consisting of alkyl groups having from 7 to 10 carbon atoms, dimethylamino alkyl groups having from 1 to 5 carbon atoms, and hydroxyalkyl groups having from 1 to 5 carbon atoms; and Zxe2x80x2xe2x80x3 is an alkyl group having from 1 to 4 carbon atoms; Rxe2x80x23 and Rxe2x80x24 are independently an alkyl group having from 8 to 18 carbon atoms; Rxe2x80x25 is hydrogen or methyl and Rxe2x80x26 is an alkyl group having from 8 to 18 carbon atoms; Rxe2x80x27 and Rxe2x80x28 are independently an alkyl group having from 8 to 18 carbon atoms; Rxe2x80x29 is an alkyl group having from 8 to 18 carbon atoms; Rxe2x80x210 and Rxe2x80x211 are independently an alkyl group having from 1 to 2 carbon atoms; Rxe2x80x212 and Rxe2x80x213 are independently selected from the group consisting of 2-pyrrolidinone, N-caprolactam, and an alkyl group having from 7 to 18 carbon atoms, with the proviso that R12 and R13 are not both 2-pyrrolidinone, are not both N-caprolactam, or are not a mixture thereof; and the copolymer has a weight average molecular weight greater than about 25,000 and is present in an amount from about 20% to about 70%.
The acidic ethylenically unsaturated monomers from (A) in this embodiment are as defined above. The ethylenically unsaturated monomers from (B) in this embodiment selected from the group of monomer formulas consisting of (i) CH2xe2x95x90C(R1)COR2; (ii) R3O OCxe2x80x94CHxe2x95x90CHxe2x80x94COOR4; (iii) CH2xe2x95x90C(R5)OCOR6; (iv) CH2xe2x95x90C(COOR7) CH2COOR8; (v) CH3CHxe2x95x90CHCOOR9; (vi) R10C6H4CR11xe2x95x90CHR11; and (vii) R12CHxe2x95x90CHR13 are as defined above. The ethylenically unsaturated monomers from (C) in this embodiment selected from the group of monomer formulas consisting of (i) CH2xe2x95x90C(Rxe2x80x21)CORxe2x80x22; (ii) Rxe2x80x23OOCxe2x80x94CHxe2x95x90CHxe2x80x94COORxe2x80x24; (iii) CH2xe2x95x90C(Rxe2x80x25)OCORxe2x80x26; (iv) CH2xe2x95x90C(COORxe2x80x27)CH2COORxe2x80x28; (v) CH3CHxe2x95x90CHCOOR9; (vi) Rxe2x80x210C6H4CRxe2x80x211xe2x95x90CHRxe2x80x211; and (vii) Rxe2x80x212CHxe2x95x90CHRxe2x80x213 are as defined above.
In this embodiment, the exact amount of acidic ethylenically unsaturated monomer from (A), ethylenically unsaturated monomer from (B), and ethylenically unsaturated monomer from (C) present in the water-dispersible copolymer is a matter of preference subject to such factors as the particular type of ethylenically unsaturated monomer employed, the molecular weight of the water-dispersible copolymer employed, and are particular to the end use application. In a preferred embodiment, the acidic ethylenically unsaturated monomer from (A) is present in the water-dispersible copolymer in an amount from about 10% to about 80%, preferably from about 15% to about 70%, and more preferably from about 20% to about 60%, by weight. In a preferred embodiment, the ethylenically unsaturated monomer from (B) is present in the water-dispersible copolymer in an amount from about 10% to about 80%, preferably from about 15% to about 70%, and more preferably from about 20% to about 60%, by weight. In a preferred embodiment, the ethylenically unsaturated monomer from (C) is present in the water-dispersible copolymer in an amount from about 10% to about 80%, preferably from about 15% to about 70%, more preferably from about 20% to about 60%, and most preferably from about 25% to about 50%, by weight.
When the amount of the acidic ethylenically unsaturated monomer from (A) exceeds the amounts set out above, the strength of the copolymer is insufficient when it is wet with a body fluid. When the amount of the acidic ethylenically unsaturated monomer from (A) is less than the amounts set out above, the dispersibility of the copolymer in water is insufficient. When the amount of the ethylenically unsaturated monomer from (B) or (C) exceeds the amounts set out above, the water repellency of the copolymer is increased which lowers the permeability to the liquid. When the amount of the ethylenically unsaturated monomer from (B) or (C) is less than the amounts set out above, the strength of the copolymer is insufficient when it is wet with the body fluid.
The water-dispersible copolymers of the present invention may be used as is, or may be partially neutralized to further control the solubility/dispersibility of the copolymer in water. When the degree of neutralization exceeds 50 molar %, however, the water-dispersible copolymer may be soluble even in water containing 0.5% of a salt. The method for the neutralization is not particularly limited. The polymerization can be followed by the neutralization or, alternatively, the monomer can be neutralized prior to the polymerization. The degree of neutralization of the water-dispersible copolymer is preferably not higher than 50 molar %, more preferably not higher than 40 molar %, and most preferably from about 5% to about 35 molar %. Examples of the alkalis which may be used for the neutralization include NaOH, KOH, LiOH, inorganic salts such as Na2CO3; and amines such as monoethanolamine, diethanolamine, triethanolamine, diethylaminoethanol, ammonia, trimethylamine and morpholine. Preferred alkalis for neutralization are NaOH, KOH, ammonia, ethanolamines, and combinations of an ethanolamine with NaOH or KOH.
The weight average molecular weight of the water-dispersible copolymers of the present invention is greater than about 25,000, preferably from about 25,000 to about 2,000,000, more preferably from about 25,000 to about 1,500,000, and most preferably from about 25,000 to about 1,250,000. When a polymerization terminator is used, the weight average molecular weight of the water-dispersible copolymers of the present invention may be lower, for example, greater than about 25,000, preferably from about 25,000 to about 2,000,000, more preferably from about 25,000 to about 1,500,000, and most preferably from about 25,000 to about 1,250,000. The acidic ethylenically unsaturated monomers from (A), the ethylenically unsaturated monomers from (B), and the ethylenically unsaturated monomers from (C) are present in any order.
As set out above, to further improve water dispersability, a chain transfer agent, or polymerization terminator, such as dodecyl mercaptan, may be added to reduce the molecular weight of the water-dispersible copolymer during the polymerization process. On the other hand, crosslinking agents may be employed to increase the molecular weight of the water-dispersible copolymer during the polymerization such as diallyl phthalate, diallyl amine, allyl methacrylate, ethylene glycol diacrylate, 1,6-hexane diacrylate, methylene, bisacrylamide, divinyl benzene, triallyl amine, triallyl cyanurate, and trimethylolpropane tawacrylate.
The precise formulation of the water-dispersible copolymers of the present invention will vary depending upon the specific end use. Other ingredients may also be incorporated into the copolymer composition as dictated by the nature of the desired composition as well known by those having ordinary skill in the art. Examples of additives traditionally used include plasticizers, tackifiers, thickeners, fillers, humectants, and surfactants which may be employed in conventional amounts.
Illustrative examples of plasticizers include acetyl tributyl citrate, butyl benzyl phthalate, butyl phthalyl butyl glycolate, dibutyl phthalate, dibutyl sebacate, diethyl phthalate, diethylene glycol dibenzoate, dipropylene glycol, dipropylene glycol dibenzoate, ethyl phthalyl ethyl glycolate, ethyl-p-toluene sulfonamide, hexylene glycol, methyl phthalyl ethyl glycolate, polyoxyethylene aryl ether, tributoxyethyl phthalate, triethylene glycol polyester of benzoic acid and phthalic acid. Of these plasticizers, dibenzoate types, phthalates, liquid polyesters or sulfonated types are preferred. When present, plasticizers are generally used in amounts of 2 to 20 parts by weight, preferably 3 to 15 parts.
Illustrative examples of tackifiers include coumarone-indene, ester gum, gum rosin, hydrocarbon resins, hydrogenated rosin, phenolic modified hydrocarbon resins, rosin esters, tall oil rosins, terpene phenolic, terpene resins, toluene-sulfonamide-formaldehyde resin, and wood rosin. When present, tackifiers are generally used in dispersion form at 40% to 65% solids in amounts up to about 50 parts by weight, preferably 2 to 20 parts.
Illustrative examples of thickeners include associative thickeners such as hydrophobically modified ethoxylated polyurethanes and hydrophobically modified alkali soluble emulsions, as well as alkali soluble emulsions. Other thickeners include oliginates, bentonite, casein, fumed silica, guar gum, gum tragacanth, hydroxy-ethylcellulose, locust bean gum, methylcellulose, polyacrylic acid salts (ammonium, potassium, sodium), polyvinyl alcohol, sodium carboxymethyl cellulose, and starches. When present, thickeners will be used in amounts up to about 25 parts by weight.
Illustrative examples of fillers include bentonites, calcium carbonate, calcium silicate, clay, mica, nut shell flours, silica, talc, uncooked starches, and wood flour. When present, fillers will be used in amounts up to about 20 parts by weight.
Illustrative examples of humectants include calcium chloride, diethylene glycol, glycerine, hexylene glycol, propylene glycol, magnesium chloride, sodium nitrate, sorbitol, sucrose, and urea. When present, humectants will be used in amounts up to about 20 parts by weight.
Surfactants are often employed in adhesive compositions to increase the penetrating effects of the adhesive. The surfactants may be one or more of anionic, cationic, amphoteric or nonionic surface-active compounds. Suitable anionic emulsifiers are, for example, alkyl sulfonates, alkylaryl sulfonates, alkyl sulfates, sulfates of hydroxylalkanols, alkyl and alkylaryl disulfonates, sulfonated fatty acids, sulfates and phosphates of polyethyoxylated alkanols and alkylphenols, as well as esters of sulfosuccinic acid. Suitable cationic emulsifiers are, for example, alkyl quaternary ammonium salts, and alkyl quaternary phosphonium salts. One type of suitable non-ionic emulsifier is the addition product of 5 to 50 moles of ethylene oxide adducted to straight-chain and branched-chain alkanols with 6 to 22 carbon atoms, or to alkylphenols higher fatty acids, higher fatty acid amines, or primary and secondary higher alkyl amines. Other suitable non-ionic emulsifiers are one or more block copolymers of propylene oxide with ethylene oxide. Preferred surfactants include fluorinated alkyl amphoterics or sodium dioctylsulfosuccinate. When present, the surfactant will be used in amounts of about 0.05 to 5.0 parts by weight.
The present invention is also directed to methods for preparing the water-dispersible copolymers in the above embodiments. The water-dispersible copolymers may be prepared by emulsion polymerization in water at a solids level from about 20% to about 70% in the presence of a surfactant or without a surfactant. No organic solvent is necessary. When the water-dispersible copolymer is polymerized without a surfactant, the monomers are first neutralized in water to a level from about 2% to about 15% molar of the acidic ethylenically unsaturated monomer from (A) to solubilize/disperse the monomers.
A polymerization initiator may be employed in the emulsion polymerization. Examples of the polymerization initiators include ammonium persulfate, sodium persulfate, hydrogen peroxide, t-butyl hydroperoxide, ascorbic acid, sodium formaldehyde sulfoxylate, sodium meta-bisulfite, dialkyl peroxides, peroxyesters, 2,2xe2x80x2-azobisisobutyronitrile, 2,2xe2x80x2-azobis(2methylbutyronitrile), 2,2xe2x80x2-azobis(2,4-dimethylvaleronitrle), 2,2xe2x80x2-azobis(2-amidinopropane) dihydrochloride, and 2,2xe2x80x2-azobis(N,N-dimethyleneisobutylamidine). The amount of the polymerization initiator ranges from about 0.01% to about 5% by weight based on the monomers. The polymerization temperature which varies depending on the selection of monomers ranges from about 30xc2x0 C. to about 90xc2x0 C. and the polymerization time ranges from about 1 to about 7 hours.
In a specific embodiment, the present invention is directed to a method for preparing an aqueous emulsion comprising a water-dispersible copolymer which is non-dispersible in aqueous solutions containing 0.5% or more of an inorganic salt, comprising the steps of:
(a) providing the following monomers in percentages by weight;
(A) from about 10% to about 90% of an acidic ethylenically unsaturated monomer; and
(B) from about 10% to about 90% of an ethylenically unsaturated monomer selected from the group of monomer formulas consisting of:
(i) CH2xe2x95x90C(R1)COR2;
(ii) R3OOCxe2x80x94CHxe2x95x90CHxe2x80x94COOR4;
(iii) CH2xe2x95x90C(R5)OCOR6;
(iv) CH2xe2x95x90C(COOR7)CH2COOR8;
(v) CH3CHxe2x95x90CHCOOR9;
(vi) R10C6H4CR11xe2x95x90CHR11; and
(vii) R12CHxe2x95x90CHR13;
xe2x80x83wherein R1 is hydrogen or methyl and R2 is xe2x80x94OZxe2x80x2 or xe2x80x94N(Zxe2x80x3)(Zxe2x80x3), wherein Zxe2x80x2 is an alkyl group having from 1 to 7 carbon atoms, and Zxe2x80x3 is independently selected from the group consisting of hydrogen and alkyl groups having from 1 to 6 carbon atoms; R3 and R4 are independently hydrogen or an alkyl group having from 1 to 7 carbon atoms, with the proviso that R3 and R4 are not both hydrogen; R5 is hydrogen or methyl and R6 is an alkyl group having from 1 to 7 carbon atoms; R7 and R8 are independently hydrogen or an alkyl group having from 1 to 7 carbon atoms, with the proviso that R7 and R8 are not both hydrogen; R9 is an alkyl group having from 1 to 7 carbon atoms; R10 and R11 are hydrogen; R12 and R13 are independently selected from the group consisting of hydrogen, xe2x80x94CN, xe2x80x94NHCHO, xe2x80x94NHCOCH3, and an alkyl group having from 1 to 7 carbon atoms; and the copolymer has a weight average molecular weight greater than about 25,000 and is present in an amount from about 20% to about 70%; and
(b) emulsion polymerizing the monomers from (A) and (B) in water at a solids level from about 20% to about 70% in the presence of a surfactant.
In another specific embodiment, the present invention is directed to a method for preparing an aqueous emulsion comprising a water-dispersible copolymer which is non-dispersible in aqueous solutions containing 0.5% or more of an inorganic salt, comprising the steps of:
(a) providing the following monomers in percentages by weight;
(A) from about 10% to about 90% of an acidic ethylenically unsaturated monomer; and
(B) from about 10% to about 90% of an ethylenically unsaturated monomer selected from the group of monomer formulas consisting of:
(i) CH2xe2x95x90C(R1)COR2;
(ii) R3OOCxe2x80x94CHxe2x95x90CHxe2x80x94COOR4;
(iii) CH2xe2x95x90C(R5)OCOR6;
(iv) CH2xe2x95x90C(COOR7)CH2COOR8;
(v) CH3CHxe2x95x90CHCOOR9;
(vi) R10C6H4CR11xe2x95x90CHR11; and
(vii) R12CHxe2x95x90CHR13;
xe2x80x83wherein R1 is hydrogen or methyl and R2 is xe2x80x94OZxe2x80x2 or xe2x80x94N(Zxe2x80x3) (Zxe2x80x3), wherein Zxe2x80x2 is an alkyl group having from 1 to 7 carbon atoms, and Zxe2x80x3 is independently selected from the group consisting of hydrogen and alkyl groups having from 1 to 6 carbon atoms; R3 and R4 are independently hydrogen or an alkyl group having from 1 to 7 carbon atoms, with the proviso that R3 and R4 are not both hydrogen; R5 is hydrogen or methyl and R6 is an alkyl group having from 1 to 7 carbon atoms; R7 and R8 are independently hydrogen or an alkyl group having from 1 to 7 carbon atoms, with the proviso that R7 and R8 are not both hydrogen; R9 is an alkyl group having from 1 to 7 carbon atoms; R10 and R11 are hydrogen; R12 and R13 are independently selected from the group consisting of hydrogen, xe2x80x94CN, xe2x80x94NHCHO, xe2x80x94NHCOCH3, and an alkyl group having from 1 to 7 carbon atoms; and the copolymer has a weight average molecular weight greater than about 25,000 and is present in an amount from about 20% to about 70%; and
(b) neutralizing the monomers from (A) and (B) in water to a level from about 2% to about 15% molar of the acidic ethylenically unsaturated monomer from (A); and
(c) emulsion polymerizing the monomers from (A) and (B) at a solids level from about 20% to about 70% without a surfactant.
In another specific embodiment, the present invention is directed to a method for preparing an aqueous emulsion comprising a water-dispersible copolymer which is non-dispersible in aqueous solutions containing 0.5% or more of an inorganic salt, comprising the steps of:
(a) providing the following monomers in percentages by weight;
(A) from about 10% to about 90% of an acidic ethylenically unsaturated monomer; and
(B) from about 10% to about 90% of an ethylenically unsaturated monomer selected from the group of monomer formulas consisting of:
(i) CH2xe2x95x90C(Rxe2x80x21)CORxe2x80x22;
(ii) Rxe2x80x23OOCxe2x80x94CHxe2x95x90CHxe2x80x94COORxe2x80x24;
(iii) CH2xe2x95x90C(Rxe2x80x25)OCORxe2x80x26;
(iv) CH2xe2x95x90C(COORxe2x80x27)CH2COORxe2x80x28;
(v) CH3CHxe2x95x90CHCOORxe2x80x29;
(vi) Rxe2x80x210C6H4CRxe2x80x211xe2x95x90CHRxe2x80x211; and
(vii) Rxe2x80x212CHxe2x95x90CHRxe2x80x213;
xe2x80x83wherein Rxe2x80x21 is hydrogen or methyl, and Rxe2x80x22 is selected from the group consisting of xe2x80x94OZxe2x80x2, xe2x80x94N(Zxe2x80x3)(Zxe2x80x3), and xe2x80x94OZxe2x80x2xe2x80x3OH, wherein Zxe2x80x2 is an alkyl group having from 8 to 18 carbon atoms; Zxe2x80x3 is independently selected from the group consisting of alkyl groups having from 7 to 10 carbon atoms, dimethylamino alkyl groups having from 1 to 5 carbon atoms, and hydroxyalkyl groups having from 1 to 5 carbon atoms; and Zxe2x80x2xe2x80x3 is an alkyl group having from 1 to 4 carbon atoms; Rxe2x80x23 and Rxe2x80x24 are independently an alkyl group having from 8 to 18 carbon atoms; Rxe2x80x25 is hydrogen or methyl and Rxe2x80x26 is an alkyl group having from 8 to 18 carbon atoms; Rxe2x80x27 and Rxe2x80x28 are independently an alkyl group having from 8 to 18 carbon atoms; Rxe2x80x29 is an alkyl group having from 8 to 18 carbon atoms; Rxe2x80x210 and Rxe2x80x211 are independently an alkyl group having from 1 to 2 carbon atoms; Rxe2x80x212 and Rxe2x80x213 are independently selected from the group consisting of 2-pyrrolidinone, N-caprolactam, 2-pyridine, 3-pyridine, 4-pyridine, and an alkyl group having from 7 to 18 carbon atoms, with the proviso that R12 and R13 are not at the same time 2-pyrrolidinone, N-caprolactam, 2-pyridine, 3-pyridine, or 4-pyridine; and the copolymer has a weight average molecular weight greater than about 25,000 and is present in an amount from about 20% to about 70%; and
(b) emulsion polymerizing the monomers from (A) and (B) in water at a solids level from about 20% to about 70% in the presence of a surfactant.
In another specific embodiment, the present invention is directed to a method for preparing an aqueous emulsion comprising a water-dispersible copolymer which is non-dispersible in aqueous solutions containing 0.5% or more of an inorganic salt, comprising the steps of:
(a) providing the following monomers in percentages by weight;
(A) from about 10% to about 90% of an acidic ethylenically unsaturated monomer; and
(B) from about 10% to about 90% of an ethylenically unsaturated monomer selected from the group of monomer formulas consisting of:
(i) CH2xe2x95x90C(Rxe2x80x21)CORxe2x80x22;
(ii) Rxe2x80x23OOCxe2x80x94CHxe2x95x90CHxe2x80x94COORxe2x80x24;
(iii) CH2xe2x95x90C(Rxe2x80x25)OCORxe2x80x26;
(iv) CH2xe2x95x90C(COORxe2x80x27)CH2COORxe2x80x28;
(v) CH3CHxe2x95x90CHCOORxe2x80x29;
(vi) Rxe2x80x210C6H4CRxe2x80x211xe2x95x90CHRxe2x80x211; and
(vii) Rxe2x80x212CHxe2x95x90CHRxe2x80x213;
xe2x80x83wherein Rxe2x80x21 is hydrogen or methyl, and Rxe2x80x22 is selected from the group consisting of xe2x80x94OZxe2x80x2, xe2x80x94N(Zxe2x80x3)(Zxe2x80x3), and xe2x80x94OZxe2x80x2xe2x80x3OH, wherein Zxe2x80x2 is an alkyl group having from 8 to 18 carbon atoms; Zxe2x80x3 is independently selected from the group consisting of alkyl groups having from 7 to 10 carbon atoms, dimethylamino alkyl groups having from 1 to 5 carbon atoms, and hydroxyalkyl groups having from 1 to 5 carbon atoms; and Zxe2x80x2xe2x80x3 is an alkyl group having from 1 to 4 carbon atoms; Rxe2x80x23 and Rxe2x80x24 are independently an s alkyl group having from 8 to 18 carbon atoms; Rxe2x80x25 is hydrogen or methyl and Rxe2x80x26 is an alkyl group having from 8 to 18 carbon atoms; Rxe2x80x27 and Rxe2x80x28 are independently an alkyl group having from 8 to 18 carbon atoms; Rxe2x80x29 is an alkyl group having from 8 to 18 carbon atoms; Rxe2x80x210 and Rxe2x80x211 are independently an alkyl group having from 1 to 2 carbon atoms; Rxe2x80x212 and Rxe2x80x213 are independently selected from the group consisting of 2-pyrrolidinone, N-caprolactam, 2-pyridine, 3-pyridine, 4-pyridine, and an alkyl group having from 7 to 18 carbon atoms, with the proviso that R12 and R13 are not at the same time 2-pyrrolidinone, N-caprolactam, 2-pyridine, 3-pyridine, or 4-pyridine; and the copolymer has a weight average molecular weight greater than about 25,000 and is present in an amount from about 20% to about 70%; and
(b) neutralizing the monomers from (A) and (B) in water to a level from about 2% to about 15% molar of the acidic ethylenically unsaturated monomer from (A); and
(c) emulsion polymerizing the monomers from (A) and (B) at a solids level from about 20% to about 70% without a surfactant.
In another specific embodiment, the present invention is directed to a method for preparing an aqueous emulsion comprising a water-dispersible copolymer which is non-dispersible in aqueous solutions containing 0.5% or more of an inorganic salt, comprising the steps of:
(a) providing the following monomers in percentages by weight;
(A) from about 10% to about 80% of an acidic ethylenically unsaturated monomer;
(B) from about 10% to about 80% of an ethylenically unsaturated monomer selected from the group of monomer formulas consisting of:
(i) CH2xe2x95x90C(R1)COR2;
(ii) R3OOCxe2x80x94CHxe2x95x90CHxe2x80x94COOR4;
(iii) CH2xe2x95x90C(R5)OCOR6;
(iv) CH2xe2x95x90C(COOR7)CH2COOR8;
(v) CH3CHxe2x95x90CHCOOR9;
(vi) R10C6H4CR11xe2x95x90CHR11; and
(vii) R12CHxe2x95x90CHR13;
xe2x80x83wherein R1 is hydrogen or methyl and R2 is xe2x80x94OZxe2x80x2 or xe2x80x94N(Zxe2x80x3)(Zxe2x80x3), wherein Zxe2x80x2 is an alkyl group having from 1 to 7 carbon atoms, and Zxe2x80x3 is independently selected from the group consisting of hydrogen and alkyl groups having from 1 to 6 carbon atoms; R3 and R4 are independently hydrogen or an alkyl group having from 1 to 7 carbon atoms, with the proviso that R3 and R4 are not both hydrogen; R5 is hydrogen or methyl and R6 is an alkyl group having from 1 to 7 carbon atoms; R7 and R8 are independently hydrogen or an alkyl group having from 1 to 7 carbon atoms, with the proviso that R7 and R8 are not both hydrogen; R9 is an alkyl group having from 1 to 7 carbon atoms; R10 and R11 are hydrogen; and R12 and R13 are independently selected from the group consisting of hydrogen, xe2x80x94CN, xe2x80x94NHCHO, and an alkyl group having from 1 to 7 carbon atoms; and
(C) from about 10% to about 80% of an ethylenically unsaturated monomer selected from the group of monomer formulas consisting of:
(i) CH2xe2x95x90C(Rxe2x80x21)CORxe2x80x22;
(ii) Rxe2x80x23OOCxe2x80x94CHxe2x95x90CHxe2x80x94COORxe2x80x24;
(iii) CH2xe2x95x90C(Rxe2x80x25)OCORxe2x80x26;
(iv) CH2xe2x95x90C(COORxe2x80x27)CH2COORxe2x80x28;
(v) CH3CHxe2x95x90CHCOORxe2x80x29;
(vi) Rxe2x80x210C6H4CRxe2x80x211xe2x95x90CHRxe2x80x211; and
(vii) Rxe2x80x212CHxe2x95x90CHRxe2x80x213;
xe2x80x83wherein Rxe2x80x21 is hydrogen or methyl, and Rxe2x80x22 is selected from the group consisting of xe2x80x94OZxe2x80x2, xe2x80x94N(Zxe2x80x3)(Zxe2x80x3), and xe2x80x94OZxe2x80x2xe2x80x3OH, wherein Zxe2x80x2 is an alkyl group having from 8 to 18 carbon atoms; Zxe2x80x3 is independently selected from the group consisting of alkyl groups having from 7 to 10 carbon atoms, dimethylamino alkyl groups having from 1 to 5 carbon atoms, and hydroxyalkyl groups having from 1 to 5 carbon atoms; and Zxe2x80x2xe2x80x3 is an alkyl group having from 1 to 4 carbon atoms; Rxe2x80x23 and Rxe2x80x24 are independently an alkyl group having from 8 to 18 carbon atoms; Rxe2x80x25 is hydrogen or methyl and Rxe2x80x26 is an alkyl group having from 8 to 18 carbon atoms; Rxe2x80x27 and Rxe2x80x28 are independently an alkyl group having from 8 to 18 carbon atoms; Rxe2x80x29 is an alkyl group having from 8 to 18 carbon atoms; Rxe2x80x210 and Rxe2x80x211 are independently an alkyl group having from 1 to 2 carbon atoms; Rxe2x80x212 and Rxe2x80x213 are independently selected from the group consisting of 2-pyrrolidinone, N-caprolactam, and an alkyl group having from 7 to 18 carbon atoms, with the proviso that R12 and R13 are not both 2-pyrrolidinone, are not both N-caprolactam, or are not a mixture thereof; and the copolymer has a weight average molecular weight greater than about 25,000 and is present in an amount from about 20% to about 70%; and
(b) emulsion polymerizing the monomers from (A), (B), and (C) in water at a solids level from about 20% to about 70% in the presence of a surfactant.
In another specific embodiment, the present invention is directed to a method for preparing an aqueous emulsion comprising a water-dispersible copolymer which is non-dispersible in aqueous solutions containing 0.5% or more of an inorganic salt, comprising the steps of:
(a) providing the following monomers in percentages by weight;
(A) from about 10% to about 80% of an acidic ethylenically unsaturated monomer;
(B) from about 10% to about 80% of an ethylenically unsaturated monomer selected from the group of monomer formulas consisting of:
(i) CH2xe2x95x90C(R1)COR2;
(ii) R3OOCxe2x80x94CHxe2x95x90CHxe2x80x94COOR4;
(iii) CH2xe2x95x90C(R5)OCOR6;
(iv) CH2xe2x95x90C(COOR7)CH2COOR8;
(v) CH3CHxe2x95x90CHCOOR9;
(vi) R10C6H4CR11xe2x95x90CHR11; and
(vii) R12CHxe2x95x90CHR13;
xe2x80x83wherein R1 is hydrogen or methyl and R2 is xe2x80x94OZxe2x80x2 or xe2x80x94N(Zxe2x80x3)(Zxe2x80x3), wherein Zxe2x80x2 is an alkyl group having from 1 to 7 carbon atoms, and Zxe2x80x3 is independently selected from the group consisting of hydrogen and alkyl groups having from 1 to 6 carbon atoms; R3 and R4 are independently hydrogen or an alkyl group having from 1 to 7 carbon atoms, with the proviso that R3 and R4 are not both hydrogen; R5 is hydrogen or methyl and R6 is an alkyl group having from 1 to 7 carbon atoms; R7 and R8 are independently hydrogen or an alkyl group having from 1 to 7 carbon atoms, with the proviso that R7 and R8 are not both hydrogen; R9 is an alkyl group having from 1 to 7 carbon atoms; R10 and R11 are hydrogen; and R12 and R13 are independently selected from the group consisting of hydrogen, xe2x80x94CN, xe2x80x94NHCHO, and an alkyl group having from 1 to 7 carbon atoms; and
(C) from about 10% to about 80% of an ethylenically unsaturated monomer selected from the group of monomer formulas consisting of:
(i) CH2xe2x95x90C(Rxe2x80x21)CORxe2x80x22;
(ii) Rxe2x80x23OOCxe2x80x94CHxe2x95x90CHxe2x80x94COORxe2x80x24;
(iii) CH2xe2x95x90C(Rxe2x80x25)OCORxe2x80x26;
(iv) CH2xe2x95x90C(COORxe2x80x27)CH2COORxe2x80x28;
(v) CH3CHxe2x95x90CHCOORxe2x80x29;
(vi) Rxe2x80x210C6H4CRxe2x80x211xe2x95x90CHRxe2x80x211; and
(vii) Rxe2x80x212CHxe2x95x90CHRxe2x80x213;
xe2x80x83wherein Rxe2x80x21 is hydrogen or methyl, and Rxe2x80x22 is selected from the group consisting of xe2x80x94OZxe2x80x2, xe2x80x94N(Zxe2x80x3)(Zxe2x80x3), and xe2x80x94OZxe2x80x2xe2x80x3OH, wherein Zxe2x80x2 is an alkyl group having from 8 to 18 carbon atoms; Zxe2x80x3 is independently selected from the group consisting of alkyl groups having from 7 to 10 carbon atoms, dimethylamino alkyl groups having from 1 to 5 carbon atoms, and hydroxyalkyl groups having from 1 to 5 carbon atoms; and Zxe2x80x2xe2x80x3 is an alkyl group having from 1 to 4 carbon atoms; Rxe2x80x23 and Rxe2x80x24 are independently an alkyl group having from 8 to 18 carbon atoms; Rxe2x80x25 is hydrogen or methyl and Rxe2x80x26 is an alkyl group having from 8 to 18 carbon atoms; Rxe2x80x27 and Rxe2x80x28 are independently an alkyl group having from 8 to 18 carbon atoms; Rxe2x80x29 is an alkyl group having from 8 to 18 carbon atoms; Rxe2x80x210 and Rxe2x80x211 are independently an alkyl group having from 1 to 2 carbon atoms; Rxe2x80x212 and Rxe2x80x213 are independently selected from the group consisting of 2-pyrrolidinone, N-caprolactam, and an alkyl group having from 7 to 18 carbon atoms, with the proviso that R12 and R13 are not both 2-pyrrolidinone, are not both N-caprolactam, or are not a mixture thereof; and the copolymer has a weight average molecular weight greater than about 25,000 and is present in an amount from about 20% to about 70%; and
(b) neutralizing the monomers from (A), (B), and (C) in water to a level from about 2% to about 15% molar of the acidic ethylenically unsaturated monomer from (A); and
(c) emulsion polymerizing the monomers from (A), (B), and (C) at a solids level from about 20% to about 70% without a surfactant.
Throughout this application, various publications have been referenced. The disclosures in these publications are incorporated herein by reference in order to more fully describe the state of the art.
Throughout this disclosure, applicant will suggest various theories or mechanisms by which applicant believes the components in the adhesive compositions function together in an unexpected manner to provide unique waterborne hot melt agents. While applicant may offer various mechanisms to explain the present invention, applicant does not wish to be bound by theory. These theories are suggested to better understand the present invention but are not intended to limit the effective scope of the claims.